<?
//====================================================
//                FileName:download.class.php
//                Summary: 文件下载类
//                Author: feifengxlq
//      Email:feifengxlq@sohu.com
//                CreateTime: 2005-7-19     
//                LastModifed:
//                copyright (c)2005 xlq.100steps.net  [email]feifengxlq@sohu.com[/email]
//   使用范例：
// $download=new download('php,exe,html',false);
//  if(!$download->downloadfile($filename))
//  {
//    echo $download->geterrormsg();
//  }      
//====================================================
class download{
  var $debug=true;
  var $errormsg='';
  var $Filter=array();
  var $filename='';
  var $mineType='text/plain';
  var $xlq_filetype=array();

  function download($fileFilter='',$isdebug=true)
  {
	$this->setFilter($fileFilter);
	$this->setdebug($isdebug);        
	$this->setfiletype();
  }
  
  function setFilter($fileFilter)
  {
    if(empty($fileFilter)) return ;
        $this->Filter=explode(',',strtolower($fileFilter));
  }
  function setdebug($debug)
  {
    $this->debug=$debug;
  }
  
  function setfilename($filename)
  {
    $this->filename=$filename;
  }
  
  function downloadfile($filename)
  {
   echo  $this->setfilename($filename);
    if($this->filecheck())
	{
	  $fn = array_pop( explode( '/', strtr( $this->filename, '\\', '/' ) ) );
	  header( "Pragma: public" );
	  header( "Expires: 0" ); // set expiration time
	  header( "Cache-Component: must-revalidate, post-check=0, pre-check=0" );
	  header( "Content-type:".$this->mineType );
	  header( "Content-Length: " . filesize( $this->filename ) );
	  header( "Content-Disposition: attachment; filename=\"$fn\"" );
	  header( 'Content-Transfer-Encoding: binary' );
	  readfile( $this->filename );
	  return true;
	}else
	{
	return false;
	}
  }
  function geterrormsg()
  {
    return $this->errormsg;
  }
  
  function filecheck()
  {
    $filename=$this->filename;
	if(file_exists($filename))
	{
	   	$filetype=strtolower(array_pop(explode('.',$filename)));
	   	if(in_array($filetype,$this->Filter))
	  	{
			//$this->errormsg.=$filename.'不允许下载！';
			//if($this->debug) exit($filename.'不允许下载！') ;
			$this->errormsg.='此文件不允许下载！';
			if($this->debug) exit('此文件不允许下载！') ;
			return false;
		}else
		{
			if ( function_exists( "mime_content_type" ) )
			{
			$this->mineType = mime_content_type( $filename );
			}
		 	if(empty($this->mineType))
		 	{
			if( isset($this->xlq_filetype[$filetype]) )  $this->mineType = $this->xlq_filetype[$filetype];
		 	}
		 	if(!empty($this->mineType))
		 	return true;
		 	else
		 	{
				//$this->errormsg.='获取'.$filename.'文件类型时候发生错误，或者不存在预定文件类型内';
				//if($this->debug) exit('获取文件类型出错');
				$this->errormsg.='获取文件类型时候发生错误，或者不存在预定文件类型内!';
				if($this->debug) exit('获取文件类型出错!');
				return false;
			}
	   	} 
	}else
	{
		//$this->errormsg.=$filename.'不存在!';
	  	//if($this->debug) exit($filename.'不存在!') ;
	  	$this->errormsg.='此文件不存在!';
	  	if($this->debug) exit('此文件不存在!') ;
	  	return false;
	}
  }
  
  function setfiletype()
  {
    $this->xlq_filetype['chm']='application/octet-stream';
    $this->xlq_filetype['ppt']='application/vnd.ms-powerpoint';
	$this->xlq_filetype['pptx']='application/vnd.ms-powerpoint';
    $this->xlq_filetype['xls']='application/vnd.ms-excel';
	$this->xlq_filetype['xlsx']='application/vnd.ms-excel';
    $this->xlq_filetype['doc']='application/msword';
	$this->xlq_filetype['docx']='application/msword';
    $this->xlq_filetype['exe']='application/octet-stream';
    $this->xlq_filetype['rar']='application/octet-stream';
    $this->xlq_filetype['js']="javascript/js";
    $this->xlq_filetype['css']="text/css";
    $this->xlq_filetype['hqx']="application/mac-binhex40";
    $this->xlq_filetype['bin']="application/octet-stream";
    $this->xlq_filetype['oda']="application/oda";
    $this->xlq_filetype['pdf']="application/pdf";
    $this->xlq_filetype['ai']="application/postsrcipt";
    $this->xlq_filetype['eps']="application/postsrcipt";
    $this->xlq_filetype['es']="application/postsrcipt";
    $this->xlq_filetype['rtf']="application/rtf";
    $this->xlq_filetype['mif']="application/x-mif";
    $this->xlq_filetype['csh']="application/x-csh";
    $this->xlq_filetype['dvi']="application/x-dvi";
    $this->xlq_filetype['hdf']="application/x-hdf";
    $this->xlq_filetype['nc']="application/x-netcdf";
    $this->xlq_filetype['cdf']="application/x-netcdf";
    $this->xlq_filetype['latex']="application/x-latex";
    $this->xlq_filetype['ts']="application/x-troll-ts";
    $this->xlq_filetype['src']="application/x-wais-source";
    $this->xlq_filetype['zip']="application/zip";
    $this->xlq_filetype['bcpio']="application/x-bcpio";
    $this->xlq_filetype['cpio']="application/x-cpio";
    $this->xlq_filetype['gtar']="application/x-gtar";
    $this->xlq_filetype['shar']="application/x-shar";
    $this->xlq_filetype['sv4cpio']="application/x-sv4cpio";
    $this->xlq_filetype['sv4crc']="application/x-sv4crc";
    $this->xlq_filetype['tar']="application/x-tar";
    $this->xlq_filetype['ustar']="application/x-ustar";
    $this->xlq_filetype['man']="application/x-troff-man";
    $this->xlq_filetype['sh']="application/x-sh";
    $this->xlq_filetype['tcl']="application/x-tcl";
    $this->xlq_filetype['tex']="application/x-tex";
    $this->xlq_filetype['texi']="application/x-texinfo";
    $this->xlq_filetype['texinfo']="application/x-texinfo";
    $this->xlq_filetype['t']="application/x-troff";
    $this->xlq_filetype['tr']="application/x-troff";
    $this->xlq_filetype['roff']="application/x-troff";
    $this->xlq_filetype['shar']="application/x-shar";
    $this->xlq_filetype['me']="application/x-troll-me";
    $this->xlq_filetype['ts']="application/x-troll-ts";
    $this->xlq_filetype['gif']="image/gif";
    $this->xlq_filetype['jpeg']="image/pjpeg";
    $this->xlq_filetype['jpg']="image/pjpeg";
    $this->xlq_filetype['jpe']="image/pjpeg";
    $this->xlq_filetype['ras']="image/x-cmu-raster";
    $this->xlq_filetype['pbm']="image/x-portable-bitmap";
    $this->xlq_filetype['ppm']="image/x-portable-pixmap";
    $this->xlq_filetype['xbm']="image/x-xbitmap";
    $this->xlq_filetype['xwd']="image/x-xwindowdump";
    $this->xlq_filetype['ief']="image/ief";
    $this->xlq_filetype['tif']="image/tiff";
    $this->xlq_filetype['tiff']="image/tiff";
    $this->xlq_filetype['pnm']="image/x-portable-anymap";
    $this->xlq_filetype['pgm']="image/x-portable-graymap";
    $this->xlq_filetype['rgb']="image/x-rgb";
    $this->xlq_filetype['xpm']="image/x-xpixmap";
    $this->xlq_filetype['txt']="text/plain";
    $this->xlq_filetype['c']="text/plain";
    $this->xlq_filetype['cc']="text/plain";
    $this->xlq_filetype['h']="text/plain";
    $this->xlq_filetype['html']="text/html";
    $this->xlq_filetype['htm']="text/html";
    $this->xlq_filetype['htl']="text/html";
    $this->xlq_filetype['rtx']="text/richtext";
    $this->xlq_filetype['etx']="text/x-setext";
    $this->xlq_filetype['tsv']="text/tab-separated-values";
    $this->xlq_filetype['mpeg']="video/mpeg";
    $this->xlq_filetype['mpg']="video/mpeg";
    $this->xlq_filetype['mpe']="video/mpeg";
    $this->xlq_filetype['avi']="video/x-msvideo";
    $this->xlq_filetype['qt']="video/quicktime";
    $this->xlq_filetype['mov']="video/quicktime";
    $this->xlq_filetype['moov']="video/quicktime";
    $this->xlq_filetype['movie']="video/x-sgi-movie";
    $this->xlq_filetype['au']="audio/basic";
    $this->xlq_filetype['snd']="audio/basic";
    $this->xlq_filetype['wav']="audio/x-wav";
    $this->xlq_filetype['aif']="audio/x-aiff";
    $this->xlq_filetype['aiff']="audio/x-aiff";
    $this->xlq_filetype['aifc']="audio/x-aiff";
    $this->xlq_filetype['swf']="application/x-shockwave-flash";
  }
}

//how to use?
/*
require_once("download_class.php");
$filename= "book1.xls";
$download=new download('xls,php,exe,html,htm',false);
if(!$download->downloadfile($filename))
{
	$msg = $download->geterrormsg();
	echo "<script>alert('$msg')</script>";
}     
*/


?>
